Who ever wrote the mass diffusion coefficient ??
 

Dear friend Who can assist me to write the Binary diffusion coefficient ?? Today ,Five species (includes H2,O2,H2O,N2,CO2)be existed inside the my model. but, i never write any UDF about binary diffusion coefficient . so, you can help me to write a simple program about this problem ... ************* you can refer to this book Book Name is Transport Phenomena Author : Bird ,R., Stewart , W., Lighfoot , E., Year : 1966 ****************** P*Dij(x,y)/[(Pc-i*Pc-j)**(1/3)*(Tc-i*Tc-j)**(5/12)*(1/Mi+1/Mj)**1/2] == 3.64*10**(-8)*[Tcell/(Tc-i*Tc-j)**(1/2)]**2.334

Tc-i critical temperature of cell of species i Tc-j critical temperature of cell of species j Pc-i critical pressure of cell of species i Pc-j critical pressure of cell of species j Mi molecular weight of the species i Mj molecular weight of the species j P total pressure Tcell temperature of cell you can use for writing this progrma by DEFINE_DIFFUSIVITY(name,c,t,i) ************************** Best regard

kevin